20564123 has 2 divisors, whose sum is σ = 20564124. Its totient is φ = 20564122.

The previous prime is 20564113. The next prime is 20564147. The reversal of 20564123 is 32146502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20564123 - 2⁶ = 20564059 is a prime.

It is a Sophie Germain prime.

It is equal to p_1304069 and since 20564123 and 1304069 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (20564113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10282061 + 10282062.

It is an arithmetic number, because the mean of its divisors is an integer number (10282062).

Almost surely, 2^20564123 is an apocalyptic number.

20564123 is a deficient number, since it is larger than the sum of its proper divisors (1).

20564123 is an equidigital number, since it uses as much as digits as its factorization.

20564123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 20564123 is about 4534.7682410461. The cubic root of 20564123 is about 273.9702446954.

The spelling of 20564123 in words is "twenty million, five hundred sixty-four thousand, one hundred twenty-three".